Jeong-Woo Lee, Georgia Tech University
Microneedles are so tiny, dozens of them can fit on the tip of a finger.
Published: Tuesday, August 24, 2010, 6:00 AM
Updated: Tuesday, August 24, 2010, 6:13 AM
Diane Suchetka, The Plain Dealer
An injection that doesn't hurt. One with needles so tiny, you barely feel them. Or no needles at all. It's not that far off. Researchers -- in the United States and around the world -- are developing several versions now. But it's not the ouchless factor that's driving their work.
Injections without jabs have benefits far greater than that, especially when it comes to helping developing countries inoculate rural communities against deadly disease.
These new shots will most likely cost less to transport, doctors or nurses won't be needed to administer them, and they'll make accidental needle sticks that can expose unsuspecting workers to blood-borne diseases such as Hepatitis C or HIV a thing of the past.
"I've gone into villages where they wash out and sterilize needles for reuse," says Dr. Lee Ponsky, a urologist at University Hospitals Case Medical Center who has traveled overseas to provide medical care. "This is a major step forward," says Ponsky, the founder of the nonprofit MedWish International.
New painless injection methods have other advantages for places like the United States, too.
One of the biggest is increasing the number of people who get inoculated -- against the flu, for example -- because patients can administer them themselves.
That's what motivated researchers at Georgia Institute of Technology and Emory University's School of Medicine in Atlanta when they began their work on microneedles.
The microneedle they're working on is a Band-Aid-like patch so small it can fit on the tip of a finger. The patch is covered with tiny, tiny needles -- from a dozen to more than 100, depending on what type of medicine is being administered and how much is needed. The needles are so short -- about as long as a piece of paper is thick -- that they never strike a nerve. They are made up of the medicine itself, mixed with an FDA-approved polymer and poured into a mold to make what look like minuscule upside-down ice cream cones, which are attached to the adhesive patch. The patient -- not a doctor or nurse -- presses the patch into his arm, and that's it.
Within a few minutes or so, the needles dissolve. All that's left is a bandage, smaller than dime, to toss in the trash.
So far, animal testing has shown no adverse effects, according to Ioanna Skountzou, a project leader in microneedle research and an assistant professor of microbiology and epidemiology at Emory's school of medicine. "No skin irritation, no systemic reactions," she says.
Even better are test results that show animals given flu vaccine with microneedles didn't become as sick from exposure to the flu and were better able to recover from it than those vaccinated with traditional needles.
"I think this will empower patients to take their medication more easily," says Mark Prausnitz, a professor of chemical and biomedical engineering at Georgia Tech who's been conducting research on microneedles for 15 years.
There's hope that the tiny patches will one day be mailed to patients so they can vaccinate themselves at home without any inconvenience at all.
"Our goal is to carry out human clinical trials within the next couple of years," says Prausnitz.
His hope, he says, is for approval from the U.S. Food and Drug Administration in about five years.
While Prausnitz and his colleagues hope for funding so they can begin human trials, researchers across the globe are working on another painless injection method called P.L.E.A.S.E.
The Painless Laser Epidermal System, developed by Pantec Biosolutions inLiechtenstein, is now being tested in humans in Europe.
Because an increasing number of medications are made up of larger molecules, they can't be absorbed into the skin unless it's punctured first, says Pantec CEO Christof B hler. That's what P.L.E.A.S.E. does.
A hand-held laser, about the size of a cordless phone, is pressed against the patient's skin. The head of the device, roughly the size of a quarter, emits intense, narrow beams of light that pierce the skin and create hundreds of micropores in just a few seconds. Because the lasers don't go deep enough to reach the nerves, it's painless, too.
Then a medicine-filled patch, like those with nicotine, is placed over the barely visible micropores. The medicine is absorbed into the skin, taken up by the blood vessels and into the body.
The testing going on now is with infertility drugs, which require women to give themselves painful daily injections. So far, B hler says, results show that P.L.E.A.S.E. is transferring the proper level of drugs to the bloodstreams of patients.
"There's a little more work to be done," B hler says. "We're a few years away from market entry."
Besides being painless, P.L.E.A.S.E. delivers medicine precisely, which allows patients to administer it themselves. And, like the microneedle, it produces no infectious waste.
"Our hope is that we can really make a difference trying to bring solutions to unmet medical needs," B hler says.
A third painless method, the jet injection, is being developed at the University of California Santa Barbara.
To understand how it works, think of a single stream of water from a shower head. Then imagine that it's as thin as a strand of a hair and it's medicine, not water.
The medicine shoots out of an injector with such force, it sends it into human skin without the use of a needle.
"A high-velocity jet pierces the skin and deposits the drug either into the skin or underneath it," says Samir Mitragotri, a chemical engineering professor at the University of California who's working on the research.
The stream of medicine is propelled by compressed gas or a compressed spring loaded into a device the size of a magic marker. Press a button, and out it shoots.
This is technology that's already out there. It has been for decades, used most often to administer insulin. But it can hurt, usually because the medication penetrates so deeply it hits nerves.
"We are trying to develop ways to keep the penetration shallow and avoid the pain," Mitragotri says.
Like the other methods, there's no risk of accidental needle sticks with a jet injector.
It's too early to say when the device might hit the market, Mitragotri says.
But he thinks it will, like the other new methods, have its own place in modern medicine.
"Eventually, I think what will happen is that each of these technologies will find its own niche," Mitragotri says. "In terms of how easy it is to use, how effective it is, how inexpensive, how controllable it is."
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